Unpaid Loss and Loss Adjustment Expense - Unpaid Loss and Loss Adjustment Expenses (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Claims Development [Line Items]
Unpaid Loss and ALAE, net	$ 124.3
Reinsurance recoverable on Unpaid Loss and ALAE, net	124.6	$ 72.7	$ 36.3
Unallocated LAE	7.3
Gross unpaid loss and LAE	256.2	$ 97.9	$ 46.3
Home and renters
Claims Development [Line Items]
Unpaid Loss and ALAE, net	46.9
Reinsurance recoverable on Unpaid Loss and ALAE, net	101.0
Gross unpaid loss and LAE	147.9
Pet
Claims Development [Line Items]
Unpaid Loss and ALAE, net	5.9
Reinsurance recoverable on Unpaid Loss and ALAE, net	11.3
Gross unpaid loss and LAE	17.2
Car
Claims Development [Line Items]
Unpaid Loss and ALAE, net	71.5
Reinsurance recoverable on Unpaid Loss and ALAE, net	12.3
Gross unpaid loss and LAE	$ 83.8